System for disposing waste packages such as diapers

ABSTRACT

Systems and methods for facilitating hygienic storage and disposal of waste packages such as used disposable diapers include a housing, a lid, and a bag unit having a bag frame and an attached single use flexible bag. The flexible bag is pleated and larger in cross-section at a lower portion than it is at the connection to the bag frame. The bag frame is releasably mounted to the housing so that it will not rotate. The lower portion of the flexible bag is positioned in a storage chamber of the housing that is shaped so as to align and center the bag. A rotatable member having radially extending flexible fingers is engaged with an intermediate portion of the bag. When the lid is closed, the rotatable member will twist the intermediate portion of the bag, sealing odors in the lower portion of the bag. A parent or caregiver will push the waste package through the resistance of the twisted intermediate portion into the lower portion of the bag, and close the lid to re-seal the twisted portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates broadly to the field of household andinstitutional waste disposal systems and processes, and morespecifically to diaper pail systems and methods for hygienically holdingand packaging particularly unsanitary and odiferous waste, such as useddiapers, for eventual disposal.

2. Description of the Related Technology

Since the introduction of disposable diapers several decades ago,parents and caregivers have struggled with the problem of how to holdunsanitary, odiferous waste packages such as used disposable diapers andwipes within an infant's changing room for eventual final disposal witha waste management service. Institutions such as hospitals and day carecenters have faced a similar problem.

Holding such waste packages in ordinary trash cans is problematic, evenwhen a lid is used, because a substantial amount of odor can and willescape into the surrounding room when the lid is removed, and again whenthe lid is replaced. In order to address this problem, diaper disposalsystems have been developed that are designed to encase the wastepackage within a plastic barrier material.

One such system has been marketed under the trademark DIAPER GENIE®. Theoriginal DIAPER GENIE® system uses a long, continuous length of plastictubing that is dispensed from an annular space within a tube-holdingcartridge that has a central opening. The consumer prepares the systemfor use by closing one end of the tubing with a knot and pushing theknotted end through the central opening. He or she then inserts a wastepackage through the central opening, and the cartridge is rotated inorder to create a twist seal in the tubing above the waste package.Additional tubing is dispensed as the cartridge is rotated. The processmay be repeated until the storage compartment in the container is full.When this occurs, the consumer must physically cut the upper end of thetube and tie another knot at the open end of the tube. Such systemsyield an awkward chain of individual waste packets within compartmentsthat are defined in the long tube by a multiplicity of twisted portions.

Such a system can be relatively complicated for the uninitiated,requiring the parent or caregiver to tie knots at both ends of the tubeand to thread the tube through the central hole when installing a tubingcartridge. While this may not be a problem for an experiencedindividual, it could cause problems for an inexperienced caregiver, suchas a young babysitter or grandparent. Using such a system could also beproblematic for a disabled individual, especially a person who hasvision problems or who lacks manual dexterity. Removing the long chainof waste packages from the storage space of such a device can also becumbersome. Such systems are also uneconomical due to the amount ofplastic tubing material used per waste package.

Another version of the DIAPER GENIE® system also requires the parent orcaregiver to pull a measured length of plastic tubing out of a cassetteand to tie a knot at the end of the tubing. The knotted portion mustthen be pushed downwardly through a pair of spring-loaded jaws into alower portion of the unit. The parent or caregiver will then insert useddisposable diapers that have been tightly rolled through a centralopening in the cartridge downwardly into the knotted tube through aportion of the tube that is clamped by the spring-loaded jaws. When thelower portion of the tube is full of used diapers, the parent orcaregiver will use an integrated cutter mechanism to cut the upperportion of the tube and close it with a knot. The tube having knots atboth ends is then pulled out of the unit and thrown away.

Unfortunately, the pressure that is created by the spring-loaded jaws inthe second version of the DIAPER GENIE® system does not always form aneffective odor seal. When a diaper is being pushed downwardly againstthe bias of the jaws, the jaws are forced open, causing opencommunication between the odiferous air in the lower portion of the tubeand the surrounding room. Accordingly, when a new waste package is beingplaced in the tube, the parent or caregiver can be exposed to anoticeable amount of odor. Inserting a waste package into such a systemcan also be an uncomfortable experience for a parent or caregiver,because his or her hand may become temporarily trapped between thespring-loaded jaws.

In both versions of the DIAPER GENIE® system, both ends of the tubingare tied with a knot rather than sealed, which under certaincircumstances can lead to leakage of liquid waste onto the floor orcarpet, the unit or the clothing of a parent or caregiver.

Another type of waste disposal system has been invented by Mr. DavidStravitz and is disclosed in U.S. Pat. Nos. 6,612,099, 6,804,930,6,851,251, 7,114,314, and 7,146,785. These systems may include acontainer that defines a waste receiving chamber, an insert defining acavity for receiving a pack of flexible tubing and an inner lid that isconnected to the container for covering or exposing an open top of theinsert. The inner lid and the insert define a dispensing opening throughwhich the tubing passes during use of the waste disposal system. Anouter lid, which is optionally pivotally connected to the container, ismovable between a position in which the waste receiving chamber isaccessible and a position in which the waste receiving chamber iscovered. A retention mechanism holds the waste package while a rotationmechanism causes rotation of the retention mechanism relative to theinsert to cause a twist to be formed above a waste package when held bythe retention mechanism. This encapsulates the waste package in thetubing.

Mr. Stravitz has more recently invented new diaper disposal systems inwhich a single use diaper pail bag has an upper end that is fixedbetween two different portions of a rigid frame that is mounted so as tobe rotationally fixed with respect to the housing of the unit. In thesesystems, which are described in pending U.S. patent application Ser.Nos. 12/172,175, 12/172,758 and 12/172,793, a rotatable member having aplurality of resilient, inwardly directed fingers is used to engage anintermediate portion of the single use bag in order to create a twistbetween upper and lower portions of the bag in order to form an odorseal. While certain principles within this system are believed to haveconsiderable promise, there has been a need for additional innovation inorder to provide a diaper disposal system of commercial quality that hasthe convenience, functionality and durability to be the best diaperdisposal system ever developed.

A need has existed for an improved diaper disposal system that is moreconvenient to load and to use, that utilizes space in a more efficientmanner and that reduces the potential for odor and liquid leakage incomparison to conventional commercial diaper disposal systems.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the invention to provide an improveddiaper disposal system that is more convenient to load and to use, thatutilizes space in a more efficient manner and that reduces the potentialfor odor and liquid leakage in comparison to conventional commercialdiaper disposal systems.

In order to achieve the above and other objects of the invention, adiaper pail assembly according to a first aspect of the inventionincludes a housing, the housing having a plurality of recesses; a bagunit having a bag frame and a flexible bag, the bag frame beingreleasably mounted to the housing so as to be prevented from rotatingwith respect to the housing, wherein the bag frame has a plurality oftabs that are respectively positioned within the plurality of recesses.

A diaper pail assembly according to a second aspect of the inventionincludes a housing, the housing having at least one recess; a bag unithaving a bag frame and a flexible bag, the bag frame being releasablymounted to the housing so as to be prevented from rotating with respectto the housing, wherein the bag frame has at least one tab that ispositioned within the recess; and wherein the housing further comprisesa locking mechanism for releasably locking the tab within said recess.

According to another aspect of the invention, a diaper pail assemblyincludes a housing; a bag unit having a bag frame and a flexible bag,the bag frame having a lower surface and being releasably mounted to thehousing so as not to rotate with respect to the housing; and wherein thehousing is constructed and arranged to permit a user to lift the bagframe from said housing by contacting the lower surface.

A diaper pail assembly according to another aspect of the inventionincludes a housing; a flexible bag releasably mounted to the housing soas not to rotate with respect to the housing; and a rotatable member fortwisting a portion of the bag, the rotatable member comprising aplurality of flexible, inwardly extending fingers, and wherein a bagcontact portion of the fingers has a kinetic frictional coefficient withrespect to like material that is substantially within a range of about0.37 to about 0.67.

A diaper pail assembly according to another aspect of the inventionincludes a housing; a flexible bag releasably mounted to the housing soas not to rotate with respect to the housing; and a rotatable member fortwisting a portion of the bag, the rotatable member comprising aplurality of inwardly extending fingers that are fabricated from anelastomeric material, and wherein said elastomeric material has ahardness that is within a range of about 60 Shore A to about 120 ShoreA.

A diaper pail assembly according to another aspect of the inventionincludes a housing; a flexible bag releasably mounted to the housing soas not to rotate with respect to the housing, the external surface ofthe flexible bag having a kinetic frictional coefficient with respect tolike material that is within a range of about 0.12 to about 0.47; and arotatable member for twisting a portion of the bag, the rotatable membercomprising a plurality of inwardly extending fingers having a bagcontact surface.

A diaper pail assembly according to another aspect of the inventionincludes a housing; a bag releasably mounted to the housing so as not torotate with respect to the housing; and a rotatable member for twistinga portion of the bag, the rotatable member comprising a plurality offlexible, inwardly extending fingers and a corresponding plurality ofspaces defined between the fingers, and wherein at least one of thespaces has a first width at a first location and a second width at asecond location, and wherein the first width is greater than the secondwidth.

A diaper pail assembly according to another aspect of the inventionincludes a housing; a bag releasably mounted to the housing so as not torotate with respect to the housing; and a rotatable member for twistinga portion of the bag, the rotatable member comprising a plurality offlexible, inwardly extending fingers, the fingers being constructed andarranged to define a central opening having a minimum diameter when thefingers are in an unstressed position, and wherein the minimum diameteris within a range of about 3 mm to about 13 mm.

A diaper pail assembly according to another aspect of the inventionincludes a housing; a bag having a bag frame, the bag frame beingreleasably mounted to said housing so as not to rotate with respect tothe housing; a rotatable member for twisting a portion of the bag, andwherein the rotatable member comprises a support member for supportingthe bag frame.

A diaper pail assembly according to another aspect of the inventionincludes a housing; a bag holder for holding a bag; a bottom surface forsupporting the bag, wherein said bottom surface comprises a curvedconcave portion for aligning and centering the bag.

A diaper pail assembly according to another aspect of the inventionincludes a housing; a lid mounted to the housing; a bag; a rotatablemember for effecting twisting of the flexible bag; and a transmissionmechanism for rotating the rotating member when the lid is closed, andwherein the transmission member includes a clutch mechanism that isconstructed and arranged to disengage when a predetermined amount offorce within said transmission mechanism is exceeded.

A diaper pail bag according to another aspect of the invention includesa flexible bag; a frame attached to the flexible bag, the frame having ahinge defined therein; and a reinforcing element for strengthening theattachment between the flexible bag and the frame at a locationproximate to the hinge.

A diaper pail bag according to another aspect of the invention includesa flexible bag; a frame attached to the flexible bag, the frame having ahinge defined therein; wherein the frame has a lower surface, andwherein the flexible bag is bonded to the lower surface.

A diaper pail bag according to another aspect of the invention includesa flexible bag, at least a portion of the flexible bag being pleated;and a frame attached to the flexible bag.

A diaper pail bag according to another aspect of the invention includesa flexible bag; and a frame attached to the flexible bag, the framehaving a hinge defined therein permitting the frame to be moved betweenopen and closed positions, and a plurality of outwardly extendingregistration projections.

A method of storing used diapers for disposal according to anotheraspect of the invention includes steps of installing a pleated flexiblebag having a first diameter at a first upper portion and a seconddiameter that is greater than the first diameter at a second lowerportion into a diaper disposal system so that said second, lower portionof said pleated flexible bag is located within a storage space of thediaper disposal system; placing at least one used diaper within thepleated flexible bag; and removing the pleated flexible bag from thediaper disposal system.

A method of opening a diaper pail bag assembly according to anotheraspect of the invention includes steps of providing a diaper pail bagassembly including a flexible bag portion and a hinged frame portionthat is attached to the flexible bag portion, the step of providing adiaper pail bag assembly being performed by providing the diaper pailbag assembly with the hinged frame portion being in a closed, foldedposition; and manipulating at least two tab members that are integralwith the hinged frame portion in order to move the hinged frame portionout of the closed position.

A method of using a diaper pail assembly according to another aspect ofthe invention includes steps of mounting an upper portion of a flexiblebag to an upper portion of a diaper bag assembly; and pushing a lowerportion of the flexible bag downwardly through a resilient rotatablesealing and gripping member having a bag engaging surface that has akinetic frictional coefficient with respect to an outer surface of theflexible bag that is substantially within a range of about 0.37 to about0.67.

A method of using a diaper pail assembly according to another aspect ofthe invention includes steps of installing a flexible bag into a diaperpail assembly, the flexible bag having an inner surface that has akinetic frictional coefficient with respect to like material that issubstantially within a range of about 0.08 to about 0.38; inserting awaste package into the flexible bag; and removing the flexible bag fromthe diaper pail assembly.

A method of using a diaper pail assembly according to a another aspectof the invention includes providing a bag assembly having a bag frameand an attached flexible bag, the bag frame having a central opening,the central opening having a minimum lateral dimension that issubstantially within a range of about 60 mm to about 180 mm; installingthe bag assembly into a diaper pail assembly; inserting a waste packageinto the flexible bag; and removing the bag assembly from the diaperpail assembly.

A method of using a diaper pail assembly according to another aspect ofthe invention includes providing a bag assembly having a bag frame thatis foldable about a hinge and that has a central opening, the bagassembly further including a flexible bag that is attached to the bagframe; installing the bag assembly into a diaper pail assembly;inserting a waste package into the flexible bag; and removing the bagassembly from the diaper pail assembly, the step of removing the bagassembly from the diaper pail assembly including a step of folding thebag frame about the hinge in order to form a carrying handle for the bagassembly.

A method of using a diaper pail assembly according to another aspect ofthe invention includes installing a flexible bag into a diaper pailassembly, the flexible bag having an outer surface and an inner surface;engaging the outer surface of the flexible bag to create a twist in theflexible bag; dispensing a powder material into an upper portion of theflexible bag above the twist; and inserting a waste package into theflexible bag by pushing the waste package downwardly through the twist,whereby a portion of the powder material is pushed with the wastepackage through the twist into a lower portion of the flexible bag.

A method of using a diaper pail assembly according to another aspect ofthe invention includes installing a flexible bag into a diaper pailassembly, the flexible bag having an outer surface, an inner surface anda lubricating material disposed on at least a portion of the innersurface; engaging the outer surface of the flexible bag to create arestricted portion in the flexible bag; and inserting a waste packageinto the flexible bag by pushing the waste package downwardly throughthe restricted portion, whereby the lubricating material facilitatespassage of the waste package through the restricted portion.

These and various other advantages and features of novelty thatcharacterize the invention are pointed out with particularity in theclaims annexed hereto and forming a part hereof. However, for a betterunderstanding of the invention, its advantages, and the objects obtainedby its use, reference should be made to the drawings which form afurther part hereof, and to the accompanying descriptive matter, inwhich there is illustrated and described a preferred embodiment of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view depicting a diaper pail assembly that isconstructed according to a preferred embodiment of the invention, shownin an open position;

FIG. 2 is a second perspective view depicting the diaper pail assemblythat is shown in FIG. 1, shown in a closed position;

FIG. 3 is a side elevational view depicting the diaper pail assemblythat is shown in FIG. 1;

FIG. 4 is a fragmentary cross-sectional view depicting a portion of thediaper pail assembly that is shown in FIG. 1;

FIG. 5 is another fragmentary cross-sectional view depicting a portionof the diaper pail assembly that is shown in FIG. 1;

FIG. 6 is a side elevational view depicting the diaper pail assemblythat is shown in FIG. 1, shown in a closed position;

FIG. 7 is a top plan view depicting the diaper pail assembly that isshown in FIG. 6;

FIG. 8 is a bottom plan view showing the diaper pail assembly that isshown in FIG. 6;

FIG. 9 is a second side elevational view showing the diaper pailassembly that is shown in FIG. 6;

FIG. 10 is a front elevational view depicting the diaper pail assemblythat is shown in FIG. 6;

FIG. 11 is a rear elevational view depicting the diaper pail assemblythat is shown in FIG. 6;

FIG. 12 is a fragmentary perspective view depicting a transmissionmechanism within the diaper pail assembly that is shown in FIG. 1;

FIG. 13 is a fragmentary perspective view depicting another portion ofthe transmission mechanism shown in FIG. 12;

FIG. 14 is a fragmentary cross-sectional view depicting another portionof the transmission mechanism shown in FIG. 12;

FIG. 15 is a fragmentary cross-sectional view depicting another portionof the diaper pail assembly that is shown in FIG. 1;

FIG. 16 is a fragmentary perspective view depicting a portion of thediaper pail assembly that is shown in FIG. 1;

FIG. 17 is a top plan view of one component of the diaper pail assemblythat is shown in FIG. 1;

FIG. 18 is a cross-sectional view taken along lines 18-18 in FIG. 17;

FIG. 19 is a cross-sectional view taken along lines 19-19 in FIG. 17;

FIG. 20 is a diagrammatical depiction of the diaper pail assembly shownin FIG. 1 in use;

FIG. 21 is a top plan view of a diaper pail bag assembly that isconstructed according to the preferred embodiment of the invention;

FIG. 22 is a bottom plan view of the diaper pail bag assembly that isshown in FIG. 21;

FIG. 23 is a cross-sectional view taken along lines 23-23 in FIG. 22;

FIG. 24 is a cross-sectional view taken along lines 24-24 in FIG. 22;

FIG. 25 is a fragmentary depiction of the diaper pail bag assembly shownin FIG. 21 in a closed position;

FIG. 26 is a diagrammatical cross-sectional view taken along lines 26-26in FIG. 25;

FIG. 27 is an isolation view of one component of the diaper pail bagassembly shown in FIG. 21;

FIG. 28 is an exploded cross-sectional view taken along lines 28-28 inFIG. 25;

FIG. 29 is an exploded cross-sectional view taken along lines 29-29 inFIG. 25; and

FIG. 30 is an exploded cross-sectional view taken along lines 30-30 inFIG. 25; and

FIG. 31 is a diagrammatical depiction of the film material that is usedin the diaper pail bag assembly shown in FIG. 21.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring now to the drawings, wherein like reference numerals designatecorresponding structure throughout the views, and referring inparticular to FIG. 1, a diaper pail assembly or system 10 that isconstructed according to a preferred embodiment of the inventionincludes a housing 12 and a lid member 14. Lid member 14 is connected tothe housing 12 by a hinge mechanism 16 so that the lid member 14 can bemoved by a parent or caregiver between an open position that is shown inFIG. 1 and a closed position that is shown in FIG. 2.

Housing 12 defines an interior storage space 13, best shown in FIG. 5,which can be accessed by a parent or a caregiver by opening a door 18.The door 18 is hingedly mounted with respect to the housing 12. Diaperpail assembly 10 further includes a base portion 20 that is constructedand arranged to support the housing 12 on an underlying horizontalsurface such as a floor or a carpet.

A latching mechanism and gripping knob 22 is provided on the door 18 forpermitting the consumer to open and close the door 18 in conventionalfashion. The latching mechanism and gripping knob 22 further includes alatch mechanism of conventional design that interengages with a portionof the housing 12 in order to selectively lock the door 18 in a closedposition as shown in FIG. 1. The door 18 is also preferably providedwith a mechanism for releasably retaining the door 18 in the openposition, so that the door 18 will not swing shut at a time that isinconvenient for the consumer.

A lid latching mechanism 24 includes a laterally expandable latch member26 that is movably mounted on the lid member 14 and a mating recess 28that is defined in the housing 12. Referring briefly to FIG. 4, a buttonor actuating surface 30 is movably mounted on a side of the lid member14 that is opposite the hinge mechanism 16 and is constrained withrespect to the lid member 14 so as to permit only substantiallyvertically upward and downward movement with respect to the lid member14. A slotted plunger member 32 is integral with an underside of theactuating surface 30 and is constructed and arranged to cam againstouter cam surfaces 25 of an opposed pair of pivotally mounted laterallyexpandable latch members 34, 36 when the actuating surface 30 isdepressed by a consumer. Latch members 34, 36 are biased by an internalspring towards the open position that is shown in FIG. 4.

When a consumer closes the lid member 14, curved lower services 27 ofthe latch members 34, 36 cam the latch members 34, 36 inwardly,permitting the recessed surfaces 29 of the respective latch members 34,36 to engage with the surface on the housing 12 that defines the recess28. This movement creates a temporary deceleration and then a sharpacceleration at the end of the lid closing process that has a tendencyto cause a small amount of odor absorbing or odor masking powder to bedispensed from a powder dispensing assembly 40 that is mounted to amating receptacle 42 that is secured to the underside of the lid member14, best shown in FIG. 1.

The powder dispensing assembly 40 and its method of operation ispreferably constructed as described in co-pending U.S. patentapplication Ser. No. 12/609,136, filed Oct. 30, 2009, the entiredisclosure of which is hereby incorporated by reference as if set forthfully herein.

Powder dispensing assembly 40 is preferably constructed and arranged todispense a deodorizing or odor-absorbing powder such as sodiumbicarbonate into a targeted area of the diaper pail assembly 10. Itpreferably includes a directional dispensing mechanism including anorifice for dispensing powder from the assembly 40 in such a manner thatinitial dispersal of the powder is concentrated to a single side of thepowder dispensing assembly 40 that is preferably away from the hingemechanism 16.

When a consumer desires to open the lid member 14 of the diaper pailassembly 10 in order to install a diaper pail bag or dispose anodiferous waste package such as a used disposable diaper, he or she willdepress the actuator button 30, which will drive the plunger 32downwardly, causing the plunger 32 to contact the outer cam surfaces 25of the respective latch members 34, 36. This will cause the latchmembers 34, 36 to disengage from the recess 28 and enable the lid member14 to be lifted upwardly.

An undercut 31 or recess is preferably defined in the housing 12 on anopposite side of housing 12 from the hinge mechanism 16 in order to givethe consumer space to be able to exert lifting pressure on a liftingsurface 33 of the lid member 14, as may be visualized by viewing FIG. 1.This will enable a parent or caregiver to easily lift the lid member 14after the lid latching mechanism 24 has been disengaged.

Referring now to FIG. 5, diaper pail assembly 10 advantageously includesstructure 44 for aligning and centering a diaper pail bag within theinterior storage space 13 of the housing 12. In the preferredembodiment, the aligning and centering structure 44 includes a bottomsurface 46 defining a lowermost extent of the interior storage space 13that includes a central, substantially flat portion 48 and an annularcurved portion 50 surrounding the substantially flat portion 48.

Alternatively, the bottom surface 46 could be entirely concavely curved,or the central portion could even have a slight convex curvature. Theportion 50 could alternatively achieve its centering and aligningfunction if it was generally flat, or even slightly convex, as long asit is raised with respect to the central portion 46 and generallyannular.

The central substantially flat portion 48 is preferably substantiallycircular in shape as viewed in top plan and has a maximum radius R₁ thatis preferably substantially within a range of about 20 mm to about 130mm, more preferably within a range of about 30 mm to about 100 mm andmost preferably within a range of about 45 mm to about 85 mm.Alternatively, the central portion 48 could have a generally oval shapeas viewed in top plan.

The annular curved portion 50 occupies a substantial portion of thebottom surface 46 and is substantially concave, having an average radiusof curvature R₂ that is preferably within a range of about 15 mm toabout 120 mm. More preferably, the average radius of curvature R₂ of theannular curved portion 50 is substantially within a range of about 25 mmto about 80 mm, and most preferably within a range of about 30 mm toabout 60 mm.

In terms of surface area, the curved concave portion 50 is preferablysubstantially at least 25% of the bottom surface 46 as a whole, morepreferably substantially at least 40% of the surface area of the bottomsurface 46 and most preferably substantially at least 60% of the surfacearea of the bottom surface 46.

The bottom surface 46 may additionally include a small upper ledgeportion 52 at its extreme outer periphery, connected to the annularconcave portion 50 by a concave portion that is shaped to provide asmooth transition between the annular concave portion 50 and the upperledge portion 52. The entire bottom surface 46 is constructed so as tohave a maximum lateral extent, which in the preferred embodiment isrepresented by a maximum radius R₃, that is preferably substantiallywithin a range of about 60 mm to about 250 mm, more preferablysubstantially within a range of about 80 mm to about 180 mm, and mostpreferably substantially within a range of about 90 mm to about 150 mm.

A ratio R₂/R₃ is preferably substantially within a range of about 0.15to about 0.95, more preferably substantially within a range of about0.20 to about 0.60, and most preferably within a range of about 0.25 toabout 0.45.

The bottom surface 46 also preferably is fabricated from a material,preferably polypropylene, that has a kinetic coefficient of frictionwith respect to like material that is substantially within a range ofabout 0.41 to about 0.71, more preferably substantially within a rangeof about 0.46 to about 0.66, and most preferably substantially within arange of about 0.51 to about 0.61.

The bottom surface 46 also preferably is fabricated from a material thathas a static coefficient of friction with respect to like material thatis substantially within a range of about 0.54 to about 0.84, morepreferably substantially within a range of about 0.59 to about 0.79, andmost preferably substantially within a range of about 0.64 to about0.74.

The bottom surface 46 and the external surface of the flexible bag 112are also preferably fabricated from materials that create a relativestatic coefficient of friction therebetween that is substantially withina range of about 0.30 to about 0.60, more preferably substantiallywithin a range of about 0.35 to about 0.55, and most preferablysubstantially within a range of about 0.40 to about 0.50.

The bottom surface 46 and the external surface of the flexible bag 112are also preferably fabricated from materials that create a relativekinetic coefficient of friction therebetween that is substantiallywithin a range of about 0.17 to about 0.47, more preferablysubstantially within a range of about 0.22 to about 0.42, and mostpreferably substantially within a range of about 0.27 to about 0.37.

The presence of the annular concave portion 50 has a beneficial effectof aligning and centering the diaper pail bag in order to enhance theeffectiveness of the twist seal 120 that will be described in greaterdetail below and to optimize the space efficiency within the flexiblebag 112 and within the internal storage space 13.

As can be visualized by viewing FIG. 20, the sloped walls of the annularportion 50 will direct the center of mass of a lower portion 116 of theflexible bag 112 radially inwardly toward a longitudinal axis of thehousing 12 of the diaper pail assembly 10. As waste packages 118 areinserted into the lower portion 116 of the flexible bag 112, theresulting expansion will tend to occur radially outwardly and evenly inall directions, thus taking advantage of the entire storage space 13within the housing 12 in a space-efficient manner. As a result, morediapers may be stored within the diaper pail assembly 10 before it needsto be emptied than would otherwise be the case.

Diaper pail assembly 10 further preferably includes a rotatable sealingand gripping member 54 that is constructed and arranged to create arestricted portion within the flexible diaper pail bag 112 in order toprovide a temporary odor seal. In the preferred embodiment, this isaccomplished by gripping and twisting the flexible diaper pail bag 112in order to provide a temporary seal, as will be described in greaterdetail below. Alternatively, the restricted portion could be created bypinching or folding a portion of the flexible bag 112 instead of bytwisting it.

A transmission mechanism 56 is provided for causing rotation of therotatable sealing member 54 for a predetermined rotational distance whenthe lid member 14 is moved from the open position shown in FIG. 1 to theclosed position shown in FIG. 2. Transmission mechanism 56 includes apush rod member 58, visible in FIGS. 1 and 12-14, that is caused andconstrained to slide linearly downwardly when the lid member 14 isclosed and linearly upwardly when it is opened. Transmission mechanism56 is designed so as not to cause any movement of the rotatable sealingmember 54 when the lid member 14 is pivoted upwardly from the closedposition to the open position.

Preferably, transmission mechanism 56 is constructed and arranged tocause the rotatable sealing member 54 to rotate a predetermined angulardistance when the lid member 14 is closed. Preferably, thispredetermined angular distance is substantially within a range of about108 degrees to about 540 degrees, more preferably substantially within arange of about of about 120 degrees to about 450 degrees and mostpreferably substantially within a range of about 162 degrees to about288 degrees.

Transmission mechanism 56 is depicted in greater detail in FIGS. 12-14.In the preferred embodiment, the push rod member 58 includes a toothedrack portion 60 that is best visible in FIG. 13. The push rod member 58is constrained to permit only vertical movement thereof with respect tothe housing 12 by a slotted channel within the internal housing frame70. A rack engaging gear 59 is mounted for rotation with respect to theinternal housing frame 70 in such a manner that it is permitted alimited amount of vertical movement with respect to the internal housingframe 70. Rack engaging gear 59 has teeth that are operatively engagedwith corresponding teeth on the toothed rack portion 60 when the rackengaging gear 59 is in its lowermost vertical position.

Transmission mechanism 56 further includes a second compound gear 62having a first gear portion 68 and a second gear portion 69 that havecommon axes of rotation and are joined for common movement except when apredetermined transmission force therebetween is exceeded, when a clutchmechanism 63 will incrementally permit relative angular displacementtherebetween in order to relieve internal forces within the transmissionmechanism 56 and avoid damage to the diaper pail assembly 10.

The first gear portion 68 is operatively engaged with the rack engaginggear 59, and the second gear portion 69 is operatively engaged with athird compound gear 65 having a first gear portion 66 and a second gearportion 67. The third compound gear 65 is formed so that the first andsecond gear portions 66, 67 are integrally formed and are mounted forcommon rotation about a common axis. The first gear portion 66 of thethird compound gear 65 is in operative engagement with the second gearportion 69 of the second compound gear 62. The second gear portion 67 ofthe third compound gear 65 is in operative engagement with a toothedrack portion 82 that is formed on an underside of a rotatable flexiblebag retaining and sealing member 54 that will be discussed in greaterdetail below.

When the lid member 14 is pivoted downwardly by a parent or caregiverfrom the open position that is shown in FIG. 1 to the closed positionthat is shown in FIG. 2, the push rod member 58 will be drivendownwardly and the rotatable flexible bag retaining and sealing member54 will be driven by the gear train mechanism 61 to rotate for thepredetermined angular distance, thereby creating a twisted portion 120in an intermediate portion 113 of the flexible bag 112 that is between alower or bottom portion 116 and an upper portion 114. This isdiagrammatically shown in FIG. 20.

The gear train mechanism 61 is operatively interconnected when the pushrod member 58 moves downwardly, because the rack engaging gear 59 is inits lowermost vertical position and operatively engaged with the secondcompound gear 62. However, when the lid member 14 is pivoted upwardlyfrom the closed position to the open position, the rack engaging gear 59is lifted upwardly out of engagement with the second compound gear 62.Accordingly the gear train mechanism 61 will be disengaged and therewill be no rotation of the flexible bag retaining and sealing member 54when the lid member 14 is opened, which allows the twisted bag to remainclosed.

As may be visualized by viewing FIG. 20, the motion of pushing the wastepackage 118 downwardly through the twisted portion 120 may have thetemporary effect of reducing the degree of twist in the twisted portion120. However, when the lid member 14 is closed, the amount of twist inthe twisted portion 120 is increased, which reinforces the quality ofthe odor seal that is created by the twisted portion 120.

In the event that the gear train mechanism 61 becomes jammed, internalforces within the gear train mechanism 61 will cause the clutchmechanism 63 to permit a relative amount of relative movement betweenthe first gear portion 68 and the second gear portion of the secondcompound gear 62. Clutch mechanism 63 includes two relatively slidablecomponents that are biased together by a spring member 64, best shown inFIG. 14, which is operatively interposed between the second compoundgear 62 and the internal housing frame 70.

Referring now to FIG. 16, the flexible bag retaining and sealing member54 preferably includes a main body portion 71 having an outer flange 72that defines an upper surface 74, which is preferably substantiallyflat. Alternatively, the upper surface 74 could be shaped so that it isslightly convex. A plurality of retaining members 76 are defined asprojections that are integral with a portion 78 of the internal housingframe 70. These are constructed and arranged to vertically constrain theflexible bag retaining and sealing member 54 so that is permitted torotate with respect to the internal housing frame 70 but is precludedfrom upward vertical movement.

The retaining members 76 and the upper surface 74 of the outer flange 72are preferably constructed and arranged to minimize relative frictiontherebetween. The relative kinetic coefficient of friction between theretaining members and the upper surface 74 is preferably substantiallywithin a range of about 0.12 to about 0.32, and more preferablysubstantially within a range of about 0.17 to about 0.27.

The relative static coefficient of friction between the retainingmembers and the upper surface 74 is preferably substantially within arange of about 0.23 to about 0.43, and more preferably substantiallywithin a range of about 0.28 to about 0.38.

In addition, a lower surface 80 of the outer flange 72 is supported forlow friction rotation with respect to the internal housing frame 70 by aplurality of bearing members 77, as is best shown in FIG. 15. In thepreferred embodiment, the bearing members 77 are positioned to bearagainst a lower surface of a lower outer flange projection 73 of theouter flange 72. Bearing members 77 are preferably fabricated out of amaterial having a relatively low coefficient of friction, such as nylon,polytetrafluoroethylene (PTFE) or polyoxymethylene (POM). Mostpreferably, bearing members 77 are fabricated from POM.

FIG. 15 also shows that the housing 12 preferably has a finger accessrecess 75 defined therein for permitting a parent or caregiver to placea finger against the lower surface 88 of the bag frame 90 in order toprise the bag frame 90 upwardly in order to disengage it from thehousing 12. The consumer will perform such an action when removing theflexible bag assembly 110 from the diaper pail assembly 10. The inherentflexibility of the bag frame 90 permits the bag frame 90 to beelastically deformed to the extent that is necessary to remove it fromthe housing 12 in this manner.

Referring again to FIG. 16, the main body portion 71 of the flexible bagretaining and sealing member 54 preferably includes an upper flangeportion 84 having a narrow, convexly curved upper surface 86 thatdefines a low friction surface for supporting a lower surface 88 of abag frame 90 that is part of a flexible bag assembly 110.

The upper surface 86 of the upper flange portion 84 preferably has akinetic frictional coefficient with respect to like material that issubstantially within a range of about 0.30 to about 0.50, and that ismore preferably substantially within a range of about 0.35 to about0.45. This ensures that the flexible bag retaining and sealing member 54can simultaneously perform the function of supporting the underside ofthe bag frame 90 while being able to freely rotate with minimalfriction. The flexible bag assembly 110 will be described in greaterdetail below.

The main body portion 71 of the flexible bag retaining and sealingmember 54 is preferably fabricated from a rigid plastic material, suchas nylon, acetyl or POM, most preferably the latter, and preferably hasa relatively low frictional coefficient with respect to like material.The flexible bag retaining and sealing member 54 further includes aradially inner resilient portion 92 including a plurality of inwardlyextending resilient finger members 94 that are configured to operativelyinteract with the flexible bag 112 in a complex manner that includesengaging the intermediate portion 113 of the flexible bag 112 to createa twisted portion 120 in order to effectively seal odors within thelower portion 116 of the flexible bag assembly 110 during use. This maybe visualized by viewing FIG. 20.

The inner resilient portion 92 of the flexible bag retaining and sealingmember 54 is also constructed in such a manner to make it easy for aparent or caregiver to push the lower portion 116 of the bag assembly110 through the central portion of the inner resilient portion 92 duringinitial installation of a flexible bag assembly 110 into the diaper pailassembly 10. This is achieved through a combination of the unique shapeof the individual resilient finger members 94, the shape of the spacesor slots 95 that are defined between the individual finger members 94and the degree of elasticity and frictional characteristics of both thefinger members 94 and the outer and inner surfaces of the flexible bag112.

FIG. 17 is a top plan view of a flexible bag retaining and sealingmember 54 that is constructed according to a preferred embodiment of theinvention. In this embodiment, six resilient finger members 94 arespaced about an inner periphery of the main body portion 71 and extendradially inwardly to a central opening 96. Six spaces or slots 95 arerespectively defined between the adjacent finger members 94, with eachof the finger members 94 and spaces 95 having substantially the sameshape and dimensions in the preferred embodiment. Alternatively, theshape of the finger members 94 and the slots 95 could be varied.

Each of the finger members 94 includes a distal, radially innermost endportion terminating at a convexly radiused tip 101 that is preferablyshaped to have a radius of curvature that is substantially within arange of about 0.5 mm to about 3.0 mm. More preferably, the convexlyradius tips 101 are shaped to have radius of curvature that issubstantially within a range of about 0.9 mm to about 1.9 mm. Tipportion 101 is also preferably thickened with respect to adjacentportions of the flexible fingers 94, as is discussed below.

The convexly radiused tips 101 of the respective finger members 94together define the central opening 96, which preferably has a minimumdiameter D₁ that is substantially within a range of about 3 mm to about13 mm, and more preferably within a range of about 5 mm to about 11 mm.Most preferably, the minimum diameter D₁ is substantially within a rangeof about 6 mm to about 10 mm.

Each of the finger members 94 is also preferably shaped so as to have apair of side edges 98, 100, each of which is curved and preferablyslightly concave so that each of the spaces defined by a pair of theopposing side edges 98, 100 is wider in a radially intermediate locationthan it is at the radially innermost location and a radially outermostlocations. The average radius of curvature of each of the side edges 98is preferably substantially within a range of about 50 mm to about 400mm, and more preferably substantially within a range of about 100 mm toabout 250 mm. The curvature of the opposing side edges 98, 100 can besubstantially constant, or it can alternatively be variable or formed oftwo or more compound curves.

As FIG. 17 shows, the finger members 94 are preferably shaped and sizedso that at least one of the spaces 95, when in an unstressed position,has a first width W₁ at a first location 102, which is preferably at anintermediate radial location along the finger members 94 where the widthof the space 95 is at a maximum. Preferably, the first location 102 islocated substantially at a radial midpoint of the opposing adjacentfinger members 94. Each space 95 further has a second width W₂ at asecond location 104, which is preferably near the distal end of therespective finger members 94 where the width is at a minimum. The firstwidth W₁ is preferably greater than the second width W₂.

The space 95 further has a third width W₃ defined at a third location106 that is preferably near the radially outermost, proximal end of therespective finger members 94 where the width is at a minimum. The firstwidth W₁ is preferably greater than the third width W₃.

The first, second and third locations 102, 104, 106 are accordinglyradially spaced from each other, with the first location 102 beingradially intermediate between the second and third locations 104, 106.

The first width W₁ is preferably substantially within a range of about 3mm to about 11 mm, more preferably substantially within a range of about4.5 mm to about 9.5 mm, and most preferably substantially within a rangeof about 6 mm to about 8 mm.

The second width W₂ is preferably substantially within a range of about0.5 mm to about 5 mm, and more preferably within a range of about 1.5 mmto about 3.5 mm.

A ratio of the first width W₁ to the second width W₂ is preferablysubstantially within a range of about 1.5 to about 4.0, and morepreferably substantially within a range of about 2.0 to about 3.5.

The third width W₃ is preferably substantially within a range of about0.5 mm to about 5 mm, and more preferably within a range of about 1.5 mmto about 3.5 mm.

A ratio of the first width W₁ to the third width W₃ is preferablysubstantially within a range of about 1.5 to about 4.0, and morepreferably substantially within a range of about 2.0 to about 3.5.

FIGS. 18 and 19 are cross-sectional views taken along lines 18-18 and19-19, respectively, in FIG. 17. These figures show that each of theresilient finger members 94 includes an upper surface 97 that is curvedconcavely with a varying radius of curvature so that the radiallyoutermost portion between the first and third locations 102, 106 asviewed in FIG. 17 has a smaller radius of curvature and is thereforemore curved than the radially innermost portion between the first andsecond locations 112, 104. Accordingly, each of the resilient fingermembers 94 initially curves downwardly from its proximal connection tothe main body portion 71 and then flattens out, extending substantiallyhorizontally from its intermediate portion to its most distal portion.The lower surfaces 99 accordingly have a convex curvature that is morepronounced in the proximal portion of the finger 94 than in the distalportion.

The lower surfaces 99 of each of the respective resilient finger members94 are also preferably spaced from the upper surface 97 so that each ofthe finger members 94 has a substantially constant thickness, which ispreferably substantially within a range of about 0.5 mm to about 3.0 mm,and more preferably substantially within a range of about 1.0 mm toabout 2.0 mm.

The distal, radially innermost tip portions 101 of the finger members 94are preferably slightly thickened with respect to the adjacent bladeportions, as is best shown in FIG. 19. The thickened tip portions 101preferably have a thickness that is preferably substantially within arange of about 1.0 mm to about 6.0 mm, and more preferably substantiallywithin a range of about 1.5 mm to about 4.5 mm.

The resilient finger members 94 are preferably fabricated from aflexible elastomeric material, which is most preferably a plasticmaterial such as a thermoplastic urethane (TPU) material having a ShoreA hardness that is preferably substantially within a range of about 60to about 120, is more preferably substantially within a range of about70 to about 110 and most preferably substantially within a range ofabout 80 to about 100. Alternatively, a thermoplastic elastomer (TPE)material or a thermoplastic resin (TPR) could be used.

The material from which the resilient finger members 94 are fabricatedpreferably has a static coefficient of friction with respect to likematerial that is substantially within a range of about 0.70 to about0.95, that is more preferably substantially within a range of about 0.80to about 0.94 and that is most preferably substantially within a rangeof about 0.85 to about 0.89. This material further preferably has akinetic coefficient of friction with respect to like material that issubstantially within a range of about 0.37 to about 0.67, morepreferably substantially within a range of about 0.42 to about 0.62 andthat is most preferably substantially within a range of about 0.47 toabout 0.57.

In addition, at least the portions of each of the resilient fingermembers 94 that will contact the flexible bag 112 preferably has astatic coefficient of friction with respect to the external surface ofthe flexible bag 112 that is substantially within a range of about 0.59to about 0.89, that is more preferably substantially within a range ofabout 0.64 to about 0.84 and that is most preferably substantiallywithin a range of about 0.69 to about 0.79. This material furtherpreferably has a kinetic coefficient of friction with respect to theexternal surface of the flexible bag 112 that is substantially within arange of about 0.34 to about 0.64, more preferably substantially withina range of about 0.39 to about 0.59 and that is most preferablysubstantially within a range of about 0.44 to about 0.54.

The external surface of the flexible bag 112 is preferably fabricatedfrom a material that has a static coefficient of friction with respectto like material that is substantially within a range of about 0.18 toabout 0.48, that is more preferably substantially within a range ofabout 0.23 to about 0.43 and that is most preferably substantiallywithin a range of about 0.28 to about 0.38. This material furtherpreferably has a kinetic coefficient of friction with respect to likematerial that is substantially within a range of about 0.12 to about0.47, more preferably substantially within a range of about 0.15 toabout 0.42 and that is most preferably substantially within a range ofabout 0.18 to about 0.38.

The internal surface of the flexible bag 112 is preferably fabricatedfrom a material that has a static coefficient of friction with respectto like material that is substantially within a range of about 0.17 toabout 0.47, that is more preferably substantially within a range ofabout 0.22 to about 0.42 and that is most preferably substantiallywithin a range of about 0.27 to about 0.37. This material furtherpreferably has a kinetic coefficient of friction with respect to likematerial that is substantially within a range of about 0.08 to about0.38, more preferably substantially within a range of about 0.13 toabout 0.33 and that is most preferably substantially within a range ofabout 0.18 to about 0.28.

FIG. 20 is a diagrammatical depiction of a diaper pail assembly 10 thatis constructed according to the preferred embodiment of the invention,shown in operation. A bag assembly 110 having a bag frame portion 90that is attached to an upper portion 114 of a flexible bag 112 isinstalled by a parent or caregiver into the diaper pail assembly 10 byseating the bag frame 90 into the housing 12 of the diaper pail assembly10 in a manner that will be described in greater detail below.

The parent or caregiver will then push the lower portion 116 of theflexible bag 112 downwardly into the internal storage space 13 of thehousing 12 by pushing it through the resilient flexible fingers 94 ofthe flexible bag retaining and sealing member 54. The lid member 14 isthen closed, which causes the flexible bag retaining and sealing member54 to rotate by a predetermined angular distance to create a twistedportion 120 in the intermediate portion 113 of the flexible bag 112.

The parent or caregiver will use the diaper pail assembly 10 byinserting a waste load package 118 such as a used disposable diaper intothe lower portion 116 of the flexible bag 112 by pushing it downwardlythrough the twisted portion 120 of the intermediate portion 113 of theflexible bag 112. This is performed against the resistance bias that isapplied by the resilience of the resilient finger members 94. As theparent or caregiver pushes the waste load package 118 downwardly throughthe twisted portion 120, the tapered, leaf-like pattern of eachresilient finger member 94 and space 95 helps the bag 112 slide alongthe opposed edges 98, 100 that define the space 95. In addition, whenthe lid member 14 is closed, the tapered, leaf-like pattern of eachresilient finger member 94 and space 95 helps to reduce drag between thebag 112 and the flexible bag retaining and sealing member 54.

The bottom portion 116 of the flexible bag 122 is not expected to movesubstantially with respect to the housing 12 during the creation of thetwisted portion 120, particularly when it is weighted down by a numberof waste packages 118. Accordingly, the degree of twist that is createdin the flexible bag 112 by the rotation of the retaining and sealingmember 54 when the lid member 14 is closed is expected to be comparableand at least equal to the predetermined amount of angular rotation ofthe retaining and sealing member 54. In practice, the degree of twist inthe flexible bag 112 will be more than the predetermined amount ofangular rotation of the retaining and sealing member 54 after insertionof the second waste package 118, because a certain amount of residualtwisting will remain in the twisted portion 120 even after the firstwaste package 118 is pushed through the twisted portion 120.

As is described in greater detail below with reference to FIG. 31, boththe external and internal surfaces of the flexible bag 112 is alsopreferably treated with a friction reducing slip agent in order tofurther reduce drag between the bag 112 and the flexible bag retainingand sealing member 54. The internal surface is further treated orimpregnated with a blocking agent in order to further reduce internalfriction both with respect to itself and with respect to the wastepackages 118.

As the consumer pushes the waste load package 118 downwardly through thetwisted portion 120, the inherent resilience of the flexible bag 112 atthe twisted portion 120 in conjunction with the inward resilient biasthat is imparted to the outer surface of the flexible bag 112 by theresilient finger members 94 keep the outermost portions of the wastepackage 118 tightly against the inner surface of the flexible bag 112,which maintains an effective odor seal even during insertion of thewaste package 118 into the lower portion 116 of the flexible bag 112.This minimizes leakage of odor from the lower portion 116 of theflexible bag 12 through the twisted portion 120 where it could bedetected by the parent or caregiver.

When the lid member 14 is closed, powder material such as sodiumbicarbonate is dispensed from the powder disperser 40 into the upperportion 114 of the flexible bag 112, above the twisted intermediateportion 113. The powder material is retained in the upper portion 114above the twisted intermediate portion 113 of the flexible bag 112 for aperiod of time before a portion of it is swept by the parent orcaregiver into the lower portion 116 of the flexible bag as the parentof caregiver pushes a waste package 118 downwardly through the twistedintermediate portion 113. The powder material accordingly deodorizes orabsorbs odor in the upper area of the diaper pail assembly 10 for aperiod of time when it is positioned within the upper portion 114 of theflexible bag 112, and later in the lower portion 116 of the flexible bag112.

The process of pushing a waste package 118 such as a wrapped, useddisposable diaper through the intermediate, twisted portion 113 of theflexible bag 112 is facilitated by the low static and kinetic frictionalcharacteristics of the innermost layer 204 of the film material 190,shown in FIG. 31. Moreover, the presence of the powder material providesadditional lubrication to the inner surface of the flexible bag 122 inthe area of the twisted intermediate portion 113.

To that end, the powder material, which is preferably sodiumbicarbonate, has a preferred granularity that is expressed as a meanparticle size maximum dimension that is substantially within a range ofabout 40 microns to about 140 microns. More preferably the mean particlesize maximum dimension is substantially within a range of about 60microns to about 120 microns and most preferably substantially within arange of about 80 microns to about 100 microns.

The powder material also preferably has a bulk density that issubstantially within a range of about 48 lb/ft³ to about 78 lb/ft³, morepreferably within a range of about 53 lb/ft³ to about 73 lb/ft³ and mostpreferably within a range of about 58 lb/ft³ to about 68 lb/ft³.

FIG. 21 is a top elevational view of a flexible bag assembly 110 that isconstructed according to a preferred embodiment of the invention.Flexible bag assembly 110 includes a flexible bag 112 that is preferablypleated so as to permit the lower portion 116 of the flexible bag 112 toexpand to a cross-sectional area that is greater than thecross-sectional area of the flexible bag 112 at its point of attachmentto the bag frame 90.

Bag frame 90 is preferably fabricated from a plastic material such ashigh density polyethylene, and includes a first portion 120 that isgenerally semicircular in shape and a second portion 122 that is alsogenerally semicircular in shape.

Bag frame 90 defines an upper surface 121, as is shown in FIG. 21, and alower surface 88 that is best shown in FIG. 22. Bag frame 90 ispreferably constructed so as to be foldable about a hinge portion 124from the open position that is shown in FIGS. 21 and 22 to the closedposition that is shown in FIG. 25. In the closed position that is shownin FIG. 25, the closure of the bag frame 90 effectively closes the upperportion 114 of the flexible bag 112 and prevents odors from escapingfrom the flexible bag 112.

In addition, the bag frame 90 when in the closed position forms aconvenient handle that is shaped and sized for a consumer toconveniently grip in order to carry the flexible bag 112, together withany waste load packages 118 that are stored therein, to a location thatis remote from the diaper pail assembly 10 for final disposal of theflexible bag 112 and the waste load packages 118.

Referring back to FIG. 21, the hinge portion 124 is preferablyintegrally molded into the bag frame 90 and is formed as a linear areathat has a reduced cross-sectional thickness, so as to permit folding ofthe bag frame 90 into the closed position. The bag frame 90 furtherincludes an annular inner surface 126 that defines a central opening 128that forms the open end of the bag frame assembly 110 when the bag frame90 is in the open position. The central opening 128 is preferablysubstantially circular and preferably has a maximum inner lateraldimension or diameter D_(i) that is substantially within a range ofabout 60 mm to about 180 mm. More preferably, the inner diameter Di issubstantially within a range of about 85 mm to about 150 mm.

Bag frame 90 also preferably is constructed to have an outercircumferential surface 130 that is preferably substantially circular inshape and that defines a minimum outer diameter D_(o) that is preferablywithin a range of about 90 mm to about 270 mm, more preferably within arange of about 120 mm to about 250 mm and most preferably within a rangeof about 140 mm to about 230 mm.

The inner diameter D_(i) represents a first diameter of the flexible bag112 at a location proximate the frame 90. The flexible bag 112 at itslower portion 116 further includes a second diameter D_(L) that ispreferably the maximum diameter of the entire flexible bag 112. Thesecond diameter D_(L) is depicted in FIG. 20, and should properly bemeasured for purposes of this document with the lower portion 116 of thebag 112 expanded to the maximum extent permitted by the construction ofthe bag 122 in a shape that is circular in transverse cross-section.Preferably, the second diameter D_(L) is larger than the first diameterD_(i).

The second diameter D_(L) is preferably substantially within a range ofabout 9 cm to about 40 cm, more preferably substantially within a rangeof about 13 cm to about 30 cm, and most preferably substantially withina range of about 15 cm to about 25 cm.

A ratio of the first diameter D_(i) to the second diameter D_(L) ispreferably substantially within a range of about 0.20 to about 0.90,more preferably substantially within a range of about 0.40 to about0.75, and most preferably substantially within a range of about 0.50 toabout 0.70.

The flexible bag assembly 110 further is constructed so as to have alength that is preferably substantially within a range of about 30 cm toabout 110 cm, more preferably within a range of about 40 cm to about 100cm, and most preferably within a range of about 50 cm to about 80 cm.

A plurality of male, radially outwardly extending projections 132, 134,136, 138 are preferably integrally formed in the bag frame 90 forpermitting secure registration of the bag frame 90 with respect to thehousing 12 of the diaper pail assembly 10 during use. Referring backbriefly to FIG. 16, a plurality of recesses 133 are defined in thehousing 12 for receiving the respective projections 132, 134, 136, 138in such a manner that the bag frame 90 is secured against rotationrelative to the housing 12 and is securely oriented and aligned in ahorizontal position when the projections 132, 134, 136, 138 are receivedwithin the respective recesses 133.

In addition, structure that is embodied as a retaining projection 135 ispreferably provided in each of the respective recesses 133 forreleasably locking the respective projection 132, 134, 136, 138 withinthe respective recess 133. The retaining projections 135 are preferablyfabricated from a substantially rigid plastic material and are integralwith the housing 12 of the diaper pail assembly 10. The inherentflexibility of the material from which the bag frame 90 is fabricatedpermits the parent or caregiver to manipulate the bag frame 90 into thesecured position wherein each of the projections 132, 134, 136, 138 arepositioned beneath the respective retaining projections 135. Similarly,the inherent flexibility of the bag frame 90 is utilized when removingthe bag frame 90 from the housing 12.

Releasable locking structure 140 is also preferably provided on the bagframe 90 in order to permit the parent or caregiver to releasably lockthe bag frame 90 into the closed position that is shown in FIG. 25. Inthe preferred embodiment, the releasable locking structure 140 includesa curved female recess 142 that is defined in the first portion 120 ofthe bag frame 90 and a mating curved male projection 144 that is definedin the second portion 122 of the bag frame 90. The curved matingportions 142, 144 advantageously and preferably extend along most of theouter periphery of the respective portions 120, 122 of the bag frame 90in order to effectively retain odors within the flexible bag assembly110 when it is in the closed position shown in FIG. 25.

The releasable locking structure 140 accordingly is constructed andarranged to define an effective odor seal as well as a locking mechanismto retain the bag frame 90 in the closed position. The curved matingportions 142, 144 preferably have a substantially constant radius andpreferably subtend an angular distance that is preferably substantiallywithin a range of about 90° to about 179°, more preferably within arange of about 120° to about 179° and most preferably within a range ofabout 150° to about 179°. The larger the angular distance covered by thecurved mating portions 142, 144, the more effective odor seal will becreated by the releasable locking structure 140.

As is shown in FIG. 22, which is a bottom plan view of the bag frame 90shown in the open position, the male, radially extending projections132, 134, 136, 138 are preferably staggered about the outer periphery ofthe bag frame 90 so that the projection pairs 134, 138 and 132, 136 areadjacent to each other but do not fully overlap when in the closedposition shown in FIG. 25. In the preferred embodiment, the projections132, 134, 136, 138 are spaced so that there is a slight but not fulloverlap between the corresponding projection pairs 134, 138 and 132,136. This permits the parent or caregiver to use his or her thumb andforefinger in order to gain leverage against one of the projection pairs134, 138 or 132, 136 in order to disengage the releasable lockingstructure 140 and move the bag frame 90 from the closed position intothe open position.

As FIG. 22 shows, each of the projections 132, 134, 136, 138 ispreferably constructed so as to have an outer surface that is convexlyabout a radial center locus 147. The radial center locus 147 of theprojection 134 is preferably spaced a first distance L₁ from a verticaltransverse centerline of the bag frame 90 and a second distance L₂ froma horizontal transverse centerline as viewed in bottom plan as shown inFIG. 22. The radial center locus 147 of the projection 132 is preferablyspaced by the second distance L₂ from the vertical transverse centerlineand by the first distance L₁ from the horizontal centerline. Theprojection 138 is preferably spaced by the first distance L₁ from thehorizontal centerline and by the second distance L₂ from the verticalcenterline, and the projection 136 is preferably spaced by the firstdistance L₁ from the vertical centerline and by the second distance L₂from the horizontal centerline.

Preferably, the first distance L₁ is less than the second distance L₂.More preferably, the first distance L₁ has a ratio with respect to thesecond distance L₂ that is preferably substantially within a range ofabout 0.60 to about 0.95 and that is more preferably within a range ofabout 0.75 to about 0.90. In an alternative embodiment, the firstdistance L₁ could be greater than the second distance L₂.

Referring now to FIG. 23, it will be seen that the female curved matingportion 142 of the releasable locking structure 140 preferably has asmall projection 150 defining an undercut for receiving and retainingthe male curved mating portion 144 in the locked position. As FIG. 24shows, the male curved mating portion 144 also preferably includes aprojection 148 for engaging the projection 150 in the female curvedmating portion 142. The female and male mating portions 142, 144 areshown in the secured positions in FIGS. 28-30.

The upper portion 114 of the flexible bag 112 has a complex andadvantageous construction in order to ensure secure attachment to thelower surface 88 of the bag frame 90. It is preferably die cut in orderto correspond to the shape of the bag frame 90.

Referring to FIGS. 22 and 25, it will be seen that a film reinforcementinsert 154 is bonded to a portion of the lower surface 88 that includesareas of the first and second portions 120, 122 as well as the hingeportion 124. The film reinforcement insert 154 is preferably fabricatedfrom a film material that is substantially identical in construction tothe film material from which the flexible bag 112 is fabricated. Itincreases the strength of the seal that is formed between the upperportion 114 of the flexible bag in the lower surface 88 of the bag frame90. It also provides the additional benefit of providing somereinforcement to the hinge portion 124.

The film reinforcement insert 154 is shown in isolation in FIG. 27 andincludes a first portion 156 that is bonded to the first portion 120 ofthe bag frame 90, as shown in FIG. 22, and a second portion 160 that isbonded to the second portion 122 of the bag frame 90. The filmreinforcement insert 154 is preferably tacked or heat sealed to thelower surface 88 using a hot tool such as a hot tip soldering iron priorto the assembly of the upper portion 114 of the flexible bag 112 to thebag frame 90.

The upper portion 114 of the flexible bag 112 further preferablyincludes a primary seal portion 162 that is bonded, tacked or heatsealed to a semicircular portion of each of the first and secondportions 120, 122 of the bag frame 91 on the lower surface 88. Theprimary seal portion 162 is integral with the upper portion 114 andincludes a first end 164, an opposite second end 166 and a curvedcentral portion 168. The first and second ends 164, 166 preferablyrespectively have broadened end portions that in the preferredembodiment are substantially circular. The first and second ends 164,166 are bonded by heat sealing to the respective film reinforcementinserts 154, which enhances the strength of the ultimate bond betweenthe first and second ends 164, 166 and the underside 88 of the bag frame90.

Referring briefly to FIG. 26, which is a diagrammatical cross-sectionalview taken along lines 26-26 in FIG. 25, the upper portion 114 of theflexible bag 112 is advantageously pleated in order to permitsignificant expandability of the lower portion 116 of the flexible bag112 with respect to the upper portion 114. The pleating is constructedand arranged in such a manner in the preferred embodiment that eachpleat 176 includes three plies 182, 184, 186 of the film material 190from which the flexible bag 112 is fabricated, with a first fold 178being defined between the first and second plies 182, 184 and a secondfold 180 being defined between the second and third plies 184, 186. Eachof the pleats 176 is preferably substantially parallel to adjacentpleats and is preferably oriented so as to extend parallel to alongitudinal axis of the flexible bag assembly 110 that is substantiallyperpendicular to the transverse plane in which the bag frame 90 ispositioned during use.

The flexible bag 112 preferably includes at least two pleats 176 aroundthe outer periphery, more preferably at least four pleats 176 and mostpreferably at least six pleats 176. In the illustrated embodiment, theflexible bag 112 has eight pleats 176.

FIG. 28 is an exploded cross-sectional view taken along lines 28-28 inFIG. 25. The primary seal 162 is constructed and arranged so that allthree plies of the upper portion 114 are bonded to each other, with theinwardmost ply 182 being directly bonded to the lower surface 88 of thebag frame 90. This is also shown in FIG. 29, which is an explodedcross-sectional view taken along lines 29-29 and FIG. 25. FIG. 30 is anexploded cross-sectional view taken along lines 30-30 in FIG. 25,showing a portion of the primary seal 162 at a portion of the upperflexible bag portion 114 between adjacent pleats 176. In this location,which is between adjacent pleats 176, only a single layer of the filmmaterial 190 overlies the lower surface 88 of the bag frame 90.

As is best shown in FIG. 25, a bag assembly 110 according to thepreferred embodiment also preferably and advantageously includes aplurality of secondary seals 170 that are formed in the upper portion114 of the flexible bag 112 in an area that is closely adjacent to thebag frame 90. The flexible bag 112 is preferably fabricated by weldingtwo sheets of the film material 190 together. One of the sheets formsthe portion of the flexible bag 112 that is bonded to the first portion120 of the bag frame 90, while the other of the sheets forms a portionof the flexible bag 112 that is bonded to the second portion 122 of thebag frame 90.

Each secondary seal includes a first end 172 and a second end 174, andis formed by creating a supplemental heat seal or weld of the two sheetsof the film material 190 together slightly beneath the bag frame 190, asis shown in FIG. 25. The first end 172 of the secondary seal 170 ispreferably separated from the bag frame 90 by a small distance D_(s)that is preferably substantially within a range of about 1 mm to about12 mm, more preferably within a range of about 3 mm to about 9 mm andmost preferably within a range of about 4 mm to about 7 mm.

The film material 190 preferably is fabricated from a material thatsubstantially prevents transmission of odors therethrough and that issubstantially liquid impervious. A preferred embodiment of the filmmaterial 190 is diagrammatically shown in FIG. 31 and includes a firstouter layer 192 that defines the outer surface of the flexible bag 112,a second layer 194, a third layer 196, a fourth layer 198, a fifth layer200, a sixth layer 202, and a seventh, inner layer 204 that defines theinner surface of the flexible bag 112.

The film material 190 preferably has a total thickness that ispreferably substantially within a range of about 15 μm to about 45 μm,and more preferably substantially within a range of about 20 μm to about40 μm.

The first and seventh external layers 192, 204 are fabricated to ensuredurability and their ability to be heat sealed together and to the bagframe 90. In addition, these layers are preferably fabricated using aslip agent in order to ensure that the coefficients of friction arewithin the predetermined ranges described above. The slip agent, whichis preferably cis-13-Docosenoamide, CAS NO.: 112-84-5, decreases theengagement between the film material 190 and the bag-engaging surfacesof the finger members 94 both when the lower portion 116 is pusheddownwardly by the user through the finger members 94, and when theintermediate portion 113 of the bag member 112 is engaged and twisted bythe finger members 94.

The first and seventh external layers 192, 204 each both preferably havea thickness that is substantially within a range of about 2.75 μm toabout 6.75 μm, and more preferably substantially within a range of about3.75 μm to about 5.75 μm. The most preferable dimensions are shown inTable 1.

An anti-block agent is also preferably provided in the external layers192, 204 in order to prevent the film material from sticking together.In the preferred embodiment a zeolite, preferably CAS NO: 1318-02-1, isused.

The second and six layers 194, 202 are fabricated to ensure durabilityand preferably include a pigmentation agent in order to provide adesired coloration. A slip agent is also preferably included in theselayers 194, 202, which is preferably cis-13-Docosenoamide, CAS NO.:112-84-5.

The second and six layers 194, 202 each both preferably have a thicknessthat is substantially within a range of about 3.25 μm to about 7.25 μm,and more preferably substantially within a range of about 4.25 μm toabout 6.25 μm. The most preferable dimensions are shown in Table 1.

Alternatively, the second and sixth layers 194, 202 could be integratedinto the first and seventh outer layers 192, 204 in order to create afive layered material. In this case, the thickness of each combinedlayer would preferably be substantially within a range of about 8.0 μmto about 12.0 μm, and more preferably substantially within a range ofabout 9.0 μm to about 11.0 μm.

The third and fifth layers 196, 200 are tie layers having the functionof binding the respective adjacent layers together. Preferably, ananhydride-modified linear low-density polyethylene (LLDPE) adhesiveresin is used, such as Dupont 41E687. The third and fifth layers 196,200 each both preferably have a thickness that is substantially within arange of about 1.75 μm to about 5.75 μm, and more preferablysubstantially within a range of about 2.75 μm to about 4.75 μm. The mostpreferable dimensions are shown in Table 1.

The fourth, middle layer 198 is a barrier layer that ensures that thefilm material 190 is substantially impervious to liquids and odortransmission. It preferably has a thickness that is substantially withina range of about 0.50 μm to about 4.50 μm, and more preferablysubstantially within a range of about 1.50 μm to about 3.50 μm. The mostpreferable dimensions are shown in Table 1.

The respective layers most preferably have a construction and athickness as described in the following table:

TABLE 1 Thickness Base Material (um/inch/% of total) 1st 66.0% mLLDPE +30.0% LDPE + 4.75 um/0.00019″/15.8% layer 3.8% slip agent + 0.2%anti-block (Outer agent by weight layer) mLLDPE is preferably ExxonMobil1018FA LDPE is preferably ExxonMobil LD100 series Slip agent ispreferably cis-13- Docosenoamide, CAS NO.: 112-84-5 Anti-block agent ispreferably Zeolite, CAS NO: 1318-02-1 2nd 66.3% mLLDPE + 28.5% LDPE +5.25 um/0.00021″/17.5% layer 3.8% slip agent + 1.4% colorant by wtmLLDPE is preferably ExxonMobil 1018FA LDPE is preferably ExxonMobilLD100 series Slip agent is preferably cis-13- Docosenoamide, CAS NO.:112-84-5 Colorant is preferably SPEM-5M1629 3rd Tie layer 3.75um/0.00015″/12.5% layer Preferably a anhydride-modified linearlow-density polyethylene (LLDPE) adhesive resin, most preferably Dupont41E687 4th Barrier layer. 2.5 um/0.0001″/8.4%  layer Preferably EVOH,most preferably Nippon Gohsei ET3803 5th Tie layer 3.75um/0.00015″/12.5% layer Preferably a anhydride-modified linearlow-density polyethylene (LLDPE) adhesive resin, most preferably Dupont41E687 6th 66.3% mLLDPE + 28.5% LDPE + 5.25 um/0.00021″/17.5% layer 3.8%slip agent + 1.4% colorant by wt mLLDPE is preferably ExxonMobil 1018FALDPE is preferably ExxonMobil LD100 series Slip agent is preferablycis-13- Docosenoamide, CAS NO.: 112-84-5 Colorant is preferablySPEM-5M1629 7th 66.0% mLLDPE + 30.0% LDPE + 4.75 um/0.00019″/15.8% layer3.8% slip agent + 0.2% anti-block (Inner agent by weight layer) mLLDPEis preferably ExxonMobil 1018FA LDPE is preferably ExxonMobil LD100series Slip agent is preferably cis-13- Docosenoamide, CAS NO.: 112-84-5Anti-block agent is preferably Zeolite, CAS NO: 1318-02-1

It is to be understood, however, that even though numerouscharacteristics and advantages of the present invention have been setforth in the foregoing description, together with details of thestructure and function of the invention, the disclosure is illustrativeonly, and changes may be made in detail, especially in matters of shape,size and arrangement of parts within the principles of the invention tothe full extent indicated by the broad general meaning of the terms inwhich the appended claims are expressed.

What is claimed is:
 1. A diaper pail assembly, comprising: a housing; abag having a bag frame, said bag frame being releasably mounted to saidhousing so as not to rotate with respect to said housing; and arotatable member for twisting a portion of said bag, wherein saidrotatable member comprises a support member for supporting said bagframe; wherein said support member comprises an upstanding projection,said upstanding projection having an upper surface that is constructedand arranged to minimize friction between said upstanding projection andsaid bag frame.
 2. A diaper pail assembly according to claim 1, furthercomprising a bottom surface for supporting the bag, wherein said bottomsurface comprises a curved concave portion for aligning and centeringthe bag.
 3. A diaper pail assembly according to claim 2, wherein saidcurved concave portion has a radius of curvature that is substantiallyconstant.
 4. A diaper pail assembly according to claim 2, wherein saidbottom portion further comprises a substantially flat central portion.5. A diaper pail assembly according to claim 1, wherein said uppersurface comprises a convexly curved surface.
 6. A diaper pail assemblyaccording to claim 1, wherein said upper surface is fabricated from amaterial having a kinetic frictional coefficient that is substantiallywithin a range of about 0.30 to about 0.50.
 7. A diaper pail assemblyaccording to claim 6, wherein said upper surface is fabricated from amaterial having a kinetic frictional coefficient that is substantiallywithin a range of about 0.35 to about 0.45.
 8. A diaper pail assemblyaccording to claim 1, wherein said bag frame is fabricated from aplastic material.
 9. A diaper pail assembly according to claim 8,wherein said plastic material comprises polyethylene.
 10. A diaper pailassembly according to claim 1, wherein said rotatable member has a bagengaging surface, and wherein a relative kinetic coefficient of frictionbetween the bag engaging surface and an external surface of the bag thatis substantially within a range of about 0.34 to about 0.64.
 11. Adiaper pail assembly according to claim 1, wherein said rotatable memberhas a bag engaging surface, and wherein a relative kinetic coefficientof friction between the bag engaging surface and an external surface ofthe bag that is substantially within a range of about 0.39 to about0.59.
 12. A diaper pail assembly, comprising: a housing; a lid mountedto said housing; a bag; a rotatable member for effecting twisting ofsaid flexible bag; and a transmission mechanism for rotating saidrotating member when said lid is closed, and wherein said transmissionmember includes a clutch mechanism that is constructed and arranged todisengage when a predetermined amount of force within said transmissionmechanism is exceeded.
 13. A diaper pail assembly according to claim 12,wherein said bag is mounted to a bag frame that is secured againstrotation with respect to said housing.